This invention is directed generally to the correction of vision and, more specifically to the reversing the effects of aging on accommodation by increasing the tension of the capsular membrane.
The normal aging process is associated with a loss of accommodative potential (presbyopia). This loss of accommodation requires the use of corrective lenses in order to perform visual tasks at near, such as reading.
Moreover, many patients have a hyperopic refractive error for which they compensate by using their accommodative potential when they are young. As they grow older, therefore, they more easily exhaust their accommodative reserve resulting in a biphasic pattern of increased dependence on optical appliances. Initially, they develop a need for corrective lenses just for near work; but eventually, they need corrective lenses for distances as well.
Patients with low to moderate myopia can compensate for presbyopia by removing their corrective lenses for near work. With the introduction of effective means for correcting myopia by photorefractive keratectomy (PRK), these patients forfeit the option when they elect to have their myopia eliminated.
The etiology of presbyopia has not been firmly established. Contributing factors identified to date include an apparent loss of ciliary muscle function, sclerosis of the crystalline lens fibers, loss of capsular tension by reduced elasticity, and crowding of the anterior segment of the eye by continued growth of the crystalline lens after puberty.
Recently, a method of restoring accommodative amplitude by expanding the equatorial circumference of the globe over the ciliary body by a variety of surgical techniques has been disclosed. These surgical techniques are quite invasive requiring deep invasions in the eyeball or the suturing of an expansive band to the eyeball.